Mapping words to actions and events: How do 18-month-olds learn a verb?

Mandy J. Maguire, Elizabeth A. Hennon, Kathy Hirsh-Pasek, Roberta M. Golinkoff, Carly B.

Slutzky, and Jenny Sootsman

The Charge

• Bloom (1994) “The diversity in young vocabularies is impressive . . . Whatever principles or assumptions are at work for word learning need to be considerably more general than those offered so far to explain how children learn names for objects”.

Thus. . .

• We need to expand our research interests beyond objects to adjectives, pronouns, and verbs.

Taking up the charge

• Adjectives (Waxman and colleagues)• Verbs

– Components of verbs (path, manner, etc.) by (Naigles, et al.; Pinker, 1984; Akhtar & Tomasello)

– Cross cultural aspects (Xu & Carey, 1996)

– Whorfian Hypothesis (Papafragou, Massey,& Gleitman 2000; Hohenstein & Naigles, 2000)

– Syntactic Approach (Gleitman, Fisher)

– Social aspects of verb learning (Tomasello)

What’s Missing

• This research has looked at sophisticated words learners, 2 years and up.

• We need to address the very beginning of verb learning, the ability to map words to actions.

Talk is in 4 parts

• Introduction to labeling actions and the action word learning problem

• 3 experiments addressing reference and extendibility in action labels

• How we interpret these experiments

• Future directions

Verbs are hard

Gentner (1982) was one of the first to address why verbs are such a problem:

• defined in diverse ways (motion, instrument, results)

• ephemeral events: not concrete

• verbs have more definitions than objects

• abstract relatedness as compared to perceptual similarity

Verbs are really really hard!

All the reasons that verbs are hard to learn may contribute to why they are so hard to study

Reference and Extendibility• Generally principles that apply to more than just

object words

• Principle of Reference – “words symbolize, or stand for, objects, actions, or events” (Hollich, Hirsh-Pasek, & Golinkoff, 2000)

• Principle of Extendibility – “most words do not refer to a single exemplar as do proper names, but to categories of objects, actions, or events” (Hollich, Hirsh-Pasek, & Golinkoff, 2000)

Running

The goal: From the study of object nouns to the study of first action words• Use proven methodology

• Bare target

• Novel stimuli

Methodology

• Proven: Split screen Preferential Looking Paradigm

• Bare: Intransitive verbs with no influence from objects or the objects’ labels

• Novel: Novel aerobics actions

The experiments

• Experiment 1 – Training with person A and extending to person Y

• Experiment 2- Training with A, B, C, and D and extending to person Y

• Experiment 3 – simplifying the action to the and extending to person Y

• Only difference between these will be the training

Procedure:

General procedure across experiments

• Subjects: 16 participants per study, range =17.92 - 21.07, M=19.36

• Procedure:– Salience trials – Training phase– Test trials– Followed by second novel action pair

• Appropriate counterbalancing

Experiment 1: Extending from one exemplar

• If one person performs all of the training can infants learn and extend the label to a novel person performing the same action?

Salience Trials

“Look up here! What’s up here? What are they doing?”

Training Phase:

“Look she’s blicking! Do you see her blicking? Watch her blicking!”

Test Phase

“Who’s blicking? Do you see her blicking? Watch her blicking!”

Predictions

• No salience preference

• If infants learn the action label and are able to extend it, they will look longer to the target action than the non-target action during the test trials than they did for the salience trials

Was there a salience preference?No

• Were they able to learn and extend an action label?

Results Test Trial Experiment 1No

Discussion Experiment 1

• Infants don’t get it

• It’s not that they aren’t paying attention

• By making it so hard we may have transformed the task into a perceptual task in which the infants prefer novelty

• Too complex?

• Too few exemplars?

Experiment 2: Extension from multiple exemplars

• Salience Trials – Same as Experiment 1

• Training - 4 distinct, female actors performing the target action consecutively

• Test Trials - Same as in Experiment 1

Was there a salience preference?No

• Were they able to learn and extend an action label?

Results Test Trials Experiment 2:• No, but they are doing better

Discussion Experiment 2

• Why aren’t they getting it?

• Too few exemplars– Fewer needed for nouns

• Each single actions is too complex

• Too much going on in scene for child to focus

Experiment 3: The ultimate simplification

Point light displays of actions

Point light images

• 13 points of light corresponding to the head and major joint points of a human.

• Infants as young as 3 months apparently see these as human forms (Bertenthal, 1984)

• 3-year-olds can recognize known actions in the IPLP and can label them when shown in point light (Golinkoff, et al.)

Procedure

• Salience – Same as Experiment 1 (live action)

• Training – Point light displays created from the exact video clip used in Experiment 1

• Test trials – Same as in Experiment 1 (live action)

Training

“Look she’s blicking! Do you see her blicking? Watch her blicking!”

Was there a salience preference?No

Were they able to learn and extend an action label?

Results Test Trials Experiment 3Yes!

t(15) = -2.536, p = .005

ConclusionsWhat do we know?

• 18-month-olds can learn action labels

• But we need to simplify the visual display

• Simplification allows infants to abstract the “verbal essence” and extend to novel agent

• Verbal essence – the semantic component of the event that is being encoded by the verb

• Verbal essence is highlighted by the point light displays

Overall results (Target – Non-target)

What we don’t know:Why it only emerged in point light

displays

• Simplicity / Focus

• Not what verbs label

Hypothesis 1: Simplicity/focus

• Single exemplar may have been complex enough to transform the task, moving towards novelty

• Multiple exemplars may begin to allow for extraction of the invariant

• Point light is less complex, therefore there are fewer options as to what to label

Two kinds of simplification

• Remove language to get categorization (Werker)

• Simple actions

Hypothesis 2: Not what verbs label

• Verbs may not label very complex actions, especially those addressed to small children

• Very few manner verbs in young lexicons (Naigles)

• By using intransitives, the verb is not anchored by a ground or goal (Gleitman, Naigles, Fisher)

• These actions may appear unmotivated and without clear intent

In Conclusion

• Infants can categorize novel actions

• Can map words to these actions (Principle of Reference)

• Can extend action labels to new instances (Principle of Extendibility)

• Part of what makes verb learning so difficult is extracting the verbal essence from complex events

Future Directions

• We are looking at the very beginning of verb learning, attaching labels to actions

• Future goal: Understand how perceptual and linguistic factors interact to permit verb learning